(1) the generation of rotor induced current

When the stator winding of the motor is connected to three-phase alternating current, will produce a rotating magnetic field rotation speed to NS between the stator and the rotor, the rotor is still at the beginning, so the rotor conductor will be rotating magnetic field cutting, according to the principle of relative motion, we can also put the magnetic field as real, and the rotor conductors relative to the magnetic field rotary cutting magnetic lines to produce electromotive force, the rotor conductor ends has been short loop short circuit conductor has to form a closed loop, so the rotor conductor also can produce induced current.

    (2) the generation of rotor electromagnetic torque

A rotor conductor induced current is electrified conductor, electrified conductor will effect in the magnetic field generated by the electromagnetic force, the electromagnetic torque of the rotor is driven to rotate, and we can also determine the direction of rotation of the rotor conductor according to the left, and the rotation direction of the magnetic field is the same, is only slightly in operation less than the speed of the speed of a rotating magnetic field. Because of this kind of N speed motor is always lower than the speed of a rotating magnetic field of NS, so this kind of motor is called asynchronous motors, because the rotor current of this kind of motor is generated by electromagnetic induction, so it is also called the induction motor.